| (19) |
 |
|
(11) |
EP 0 228 136 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
21.03.1990 Bulletin 1990/12 |
| (43) |
Date of publication A2: |
|
08.07.1987 Bulletin 1987/28 |
| (22) |
Date of filing: 18.12.1986 |
|
| (51) |
International Patent Classification (IPC)4: G09G 1/16 |
|
| (84) |
Designated Contracting States: |
|
DE FR GB IT |
| (30) |
Priority: |
30.12.1985 US 815362
|
| (71) |
Applicant: Philips Electronics N.V. |
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5621 BA Eindhoven (NL) |
|
| (72) |
Inventors: |
|
- Kaplinsky, Cecil Hertz
NL-5656 AA Eindhoven (NL)
- Li, Jan-Kwei Jack
NL-5656 AA Eindhoven (NL)
|
| (74) |
Representative: Strijland, Wilfred et al |
|
INTERNATIONAAL OCTROOIBUREAU B.V.,
Prof. Holstlaan 6
5656 AA Eindhoven
5656 AA Eindhoven (NL) |
|
| |
|
| (54) |
Abstract operation-signalling from a raster scan video controller to a display memory |
(57) A generalized operation-signalling logic for a raster scan video controller whereby
the video controller, in accessing the memory of a computer system, can indicate what
type of operation is to be performed at each memory address to be accessed. The signalling
scheme provides a rich set of functions, logic to generate this signalling and an
external PLA-type device which interprets this signalling for a wide variety of memory
types.